Many coffee drinkers roll out of bed and get their daily dose of java as soon as possible. Because of the way coffee affects our bodies, though, there may be more ideal times to drink it.

Neuroscience PhD student Steven Miller explains that in the mornings (between the hours of 8 am and 9 am) our cortisol levels are at their highest. Cortisol isn't just the "stress hormone"—it's also correlated with our alertness levels.

So if we drink coffee at the same time our alertness is already at its peak, we're wasting the potential alertness boost we get from the caffeine:

One of the key principles of pharmacology is use a drug when it is needed (although I’m sure some scientists might argue that caffeine is always needed). Otherwise, we can develop tolerance to a drug administered at the same dose. In other words, the same cup of morning coffee will become less effective

The most effective time to have a cup of joe, Miller says, is between 9:30 am and 11:30 am. (Between noon and 1 pm and between 5:30 pm and 6:30 pm are other times cortisol levels rise, so you might want to avoid drinking coffee during those hours.)

If you're going to drink more than one cup of coffee, though, a cup or less every hour will also give you the best bang for your caffeinated buck.